Surface controlled float valve and inside blowout preventer drilling tool

ABSTRACT

A full bore opening rotatable ball valve inside blow-out preventer well tool adapted for connection in a well conduit to automatically control undesired flow in the bore therethrough and including a releasable locking means for holding the ball valve in open position when running the tool into the well bore and which is released by a predetermined manipulation of the drilling string to enable the well pressure responsive operation of the ball valve.

Unlted States Patent 1 1 1111 3,835,925

Mott 1 Sept. 17, 1974 [5 SURFACE CONTROLLED FLOAT VALVE 3,442,327 5/1969 on-trrr 166/226 AND INSIDE BLOWOUT PREVENTER 3,442,328 5/1969 Nutter... 166/226 3,628,605 12/1971 Kirkpatrick 166/226 DRILLING TOOL 3,667,557 6/1972 TOOd et 61, 1. 175/318 [75] Inventor: James D. Mott, Houston, Tex.

[73] Assignee: Hydril Company, Houston, Tex.

[22] Filed: May 14, 1973 [21] Appl. No.: 359,685

[52] US. Cl. 166/73, 166/224 [51] Int. Cl E211) 43/12 [58] Field of Search 166/73, 226, 224

[56] References Cited UNITED STATES PATENTS 3,200,837 9/1962 Brown 175/318 3,386,701 6/1968 Potts 166/226 3,414,059 12/1968 Nutterm. 166/226 3,414,061 12/1968 Nutter 166/226 Primary ExaminerJames A Leppink Attorney, Agent, or FirmPravel, Wilson & Matthews ABSTRACT 18 Claims, 10 Drawing Figures PAIENIEBSEPI mu sum w 5:

SURFACE CONTROLLED FLOAT VALVE AND INSIDE BLOWOUT PREVENTER DRILLING TOOL CROSS-REFERENCES TO RELATED APPLICATIONS The present application is related to my co-pending applications, Ser. No. 201,878, entitled Drilling Tool, now US. Pat. No. 3,783,942 and Ser. No. 212,260, also entitled Drilling Tool.

BACKGROUND OF THE INVENTION This invention relates generally to the field of well .tools and more particularly to a surface controlled float open position for enabling filling of the bore of the drill string through the drill bit to preclude collapsing of the string by fluid pressure when running back in the well.

While those tools have served a most useful purpose, they did require running and retrieval trips of wire-line tools to either lock open or release the ball element. Such trips were time-consuming, and therefore, undesirable due to the expense of the drilling time lost during such trips.

SUMMARY OF THE INVENTION A full bore opening rotatable ball valve inside blowout preventer drilling tool adapted for connection in a drilling string and having a releasable locking means for holding the ball valve in the open position when running in the well bore and which is released by a predetermined manipulation of the drilling string to enable well pressure responsive operation of the ball valve.

An object of the present invention is to provide a new and improved inside blowout preventer drilling tool.

Another object of the present invention is to provide a new and improved surface controlled float valve drilling tool.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A, 1B and 1C are side views, partially in section, arranged in sequence from top to bottom of the drilling tool of the present invention in the locked open configuration;

FIGS. 2A and 2B are side views, partially in section similar to FIGS. 1A and 1B, respectively, illustrating the drilling tool in the closed condition during unlock- FIGS. 3A and 3B are views similar to FIGS. 2A and 2B, respectively, illustrating the drilling tool in the closed position after unlocking;

FIGS. 4A and 4B are views similar to FIGS. 3A and 38, respectively, illustrating the drilling tool in the open position after unlocking; and

FIG. 5 is a view taken along line 5--5 of FIG. 4A.

DESCRIPTION OF THE PREFERRED EMBODIMENT The well tool of the present invention, generally designated T in the Figs. includes a housing H adapted for connection in a well conduit C to position the tool T for controlling undesired upwardly flow of fluid in a bore F of the well conduit C. The tool T includes a bore closure means B disposed in a bore or opening 0 extending through the tubular housing H and a means for releasably holding the bore closure means B in the open position and which is actuated to release the bore closure means B by predetermined manipulation of the well conduit C to enable movement of the bore closure means B to control flow of fluid through the bore O of the housing H.

The housing H is connectable in the well conduit or tubing C to form a portion and having the longitudinally extending bore 0 formed therethrough communicating the bore or flow passage F of the well conduit C above and below the housing H. The bore 0 of the housing H is of substantially the same diameter or cross-sectional flow area as the flow passage F of the conduit C and aligned therewith to provide a full opening well tool enabling the running of other well tools through the bore 0 of the housing H when desired. The conduit C is preferably a drilling string well conduit, but the tool T of the present invention may be employed in any flow conducting conduit and should not be considered limited to use in either a well or a drilling string.

As illustrated in FIGS. 1A, 1B and 1C, the housing H extends downwardly from an upper box or threaded connection 10 (FIG. 1A) to a lower threaded connection 1 1 (FIG. 1C) which is preferably, but not necessarily, a box connection also, to enable the connection of the well tool T in a drill string C immediately above a drilling bit (not illustrated) as is well known. The housing H includes an upper tubular section or first housing portion 12 and a lower tubular section or second housing portion 13 which is connected with the upper tubular section and longitudinally movable relative thereto in a telescoping manner to and from a tool extended or elongated position and a tool contracted or shortened position. The lower tubular section 13 extends upwardly from a downwardly facing annular shoulder 13a adjacent the box threads 11 (FIG. 1C) to an upwardly facing annular shoulder 13b (FIG. 18) while the upper tubular section 12 extends upwardly from a downwardly facing annular shoulder 12a (FIG. 1C) to an upwardly facing annular shoulder 12b adjacent the threads 10. For ease of assembly of the tool T, the upper tubular section 12 is formed of tubular members 12c, 12d and 12e secured together by fluid leakage blocking threaded engagement at 12f and 12g and with the upper tubular section 12 further including a sleeve 14 concentrically disposed adjacent a bore defining inner surface l2i of the upper tubular section 12 adjacent the sleeve l2e. The sleeve 14 (FIGS. 1A & 1B) is secured with the tubular section 12 by engagement of an upwardly facing annular shoulder 14a thereof with a downwardly facing tapered annular shoulder 12h formed by the surface l2i and which is blocked from downwardly movement by a keeper pin 15 (FIG. 1A) received in a recess 14b of the sleeve 14 and which is secured to the sleeve 12e by threaded engagement at 15a. As illustrated in FIG. 1B. the sleeve 14 mounts an O-ring 14c to block leakage of fluid between the sleeve 14 and the sleeve 12e.

As also illustrated in FIG. 1B the upper tubular section 12 is mounted with the lower tubular section 13 to enable relative longitudinal movement therebetw een while blocking relative circumferential rotational movement between the concentrically arranged tubular sections 12 and 13 for transmitting rotary motion therebetween to enable the use of the well tool T of the present invention in a rotary drill string C. The lower tubular section 13 includes a plurality of radially outwardly projecting lugs 130 formed on an outer surface 13d of the tubular section 13 adjacent the sleeve 12d which mounts a plurality of radially inwardly projecting lugs or ears l2j which extend between the ears 13c for providing a spline or keyed arrangement to enable relative longitudinal movement therebetween while preventing relative rotational movement. As illustrated in FIG. 2B, the inner surface l2i of the sleeve 12 forms a downwardly facing annular shoulder 12k which limits relative contracting telescopic movement between the upper tubular section 12 and the lower tubular section 13 (FIG. 23) while a ring member 16 mounted above the sleeve 12c and adjacent threads 12f provides a stop to limit the telescoping longitudinal movement at the extended position (FIG. 1B).

As illustrated in FIG. 1C, the tool T includes a mounting ring 20 concentrically located between the sleeve 12c and the sleeve 13, a resiliently deformable tubular unit 21 and a lower guide ring 22 all of which cooperate to provide a means for dampening transmission of vibrations and shock incurred during the rotary drilling operations by the drill bit from the lower tubular section 13 to the upper tubular section 12. The guide ring 22 engages the sleeve 12c adjacent the shoulder 12a to maintain the upper tubular section 12 and the lower tubular section 13 in concentric alignment despite relative longitudinal movement therebetween. The inner surface 12i tubular section 12 is recessed at 12m for receiving therein a portion of the deformed resilient or buffering unit 21 when the upper tubular section 12 and the lower tubular section 13 are in the relative contracted position (FIGS. 2B and 4B). The resilient unit 22 when deformed into the condition illustrated in FIG. 43, either absorbs or transmits to the upper tubular section 12 with a smaller amplitude, shocks and vibrations incurred by the drill bit during drilling operations. The resilient unit 21 is preferably formed of any suitable and readily avaliable hightemperature compatible rubber-like material to enable the use of the tool T when the temperature incurred in drilling operations is relatively high. The resilient unit is preferably secured to both the guide ring 22 and the mounting ring 20 by any suitable means to form a single unit for ease of assembly. A shear pin 16 to prevent inadvertent or undesired relative telescoping movement between the upper tubular section 12 and the lower tubular section 13 is received in a recess 13d of the sleeve 13 and is threadedly secured to the sleeve 12c by threaded engagement at 16a The lower tubular section 13 mounts an annular sealing element 17 effecting a sliding seal with the surface l2i to block leakage of fluid between the upper and lower tubular sections 12 and 13.

As illustrated in FIGS. 1A and 1B, the well too] T includes the bore closure means B and an operator or actuator means, generally designated A, for effecting movement of the bore closure means B to and from the open and closed positions. The actuator means A includes a sleeve 30 disposed in the bore and mounted with the housing H adjacent the sleeve l2e and a pivot means or pins 31. The operator sleeve 30 is longitudinally movable in the bore 0 to and from a lower or first position (FIG. 4A) for effecting movement of the bore closure means B to the open position and to and from an upper or second position for effecting movement of the bore closure means B to the closed position for blocking flow of fluid through the bore 0 of the housing H (FIG. 3A). The operator 30 extends downwardly from a tapered upwardly facing annular shoulder 30a which engages a downwardly facing annular shoulder 1211 provided by the inner surface 121' to limit upwardly movement of the operator sleeve 30 to a plurality of tapered downwardly facing shoulders 30b arranged in an annular-like manner and formed by a corresponding plurality of circumferentially spaced downwardly extending resilient members or prongs 300. The operator sleeve 30 includes an outer surface 30d which is stepped to provide a downwardly facing annular shoulder at 30e for engaging the shoulder 14a of the sleeve 14 to limit downward movement of the operator sleeve 30 and for providing a smaller diameter outer surface portion 30f adjacent the sleeve 14. The operator 30 mounts annular sealing elements 32 and 33 on the surfaces 30e and 30f, respectively, to effect a sliding seal with the surfaces l2i of the sleeve l2e and an inner surface of the sleeve 14 to block leakage of fluid therebetween. The seals effected by the elements 32 and 33 along with that of the O-ring 14c define an annular expansible chamber 34 which communicates with the area adjacent an exterior surface 12p of the upper section 12 through a port or passageway l2q. Thus, fluid pressure adjacent the exterior surface 12p of the tool T will be communicated into the chamber 34 through the port or passageway l2q for urging on the pressure responsive shoulder 30e to move the operator sleeve 30 upwardly in response to the pressure in the annular chamber 34. The actuator means A further includes an urging or spring means 35 disposed in concentric relationship between the sleeve 14 and the operator sleeve 30 adjacent the keeper pin 15. The fixed sleeve 14 provides an upwardly facing annular shoulder 14d for mounting the spring 35 with the housing H and with an upper end 35a of the spring 35 engaging a downwardly facing annular shoulder 30g, located below the sealing element 33, the spring 35 serves to urge the operator sleeve 30 to the upper position.

The bore closure means B is located in the bore 0 of the housing H adjacent an inner surface 30x of the operator sleeve 30 which defines a full opening flow passage through the operator 30. Preferably, the bore closure means B includes a rotatable ball valve element 40 having a flow port 40a formed therethrough of substantially the same inner diameter or flow area as the inner diameter of the flow passage F of the drill string C to provide a full bore opening well tool T. The ball member 40 is rotatable to and from an open position (FIG. 4A) aligning the flow port 40a with the bore 0 of the housing H for enabling flow of fluid through the well tool T and the closed position to position the flow port 40a transversely to the bore 0 of the housing H for substantially blocking flow of fluid through the bore 0 with the ball member 40. The ball member 40 includes an outer spherical surface 40b engaging an annular seal ring 41 mounted with the operator sleeve 30 above the ball 40 for effecting an annular seal therebetween to block passage of fluid between the ball and the seal ring 41. The seal ring 41 is sealed to the operator sleeve 30 by an O-ring 41a to block passage or leakage of fluid between the seal ring 41 and the operator sleeve 30. The ball 30 includes a pair of parallel flat surfaces 400 with each surface 40c having a radially extending slot or recess 40d formed therein for receiving a portion of one of the longitudinally aligned pivot pins 31 therein. Relative longitudinal movement between the ball 40 and the pivot pins 31 will effect a 90 rotation of the ball between the open and closed position. The assembly and operation of the rotatable ball 40 in the well tool T is set forth in greater detail in my co-pending application Ser. No. 256,194, entited Pressure Operated Safety Valve With Lock Means to which specific reference is made for incorporating that disclosure herein.

The well tool T further includes means, generally designated L in the Figs., for releasably holding or locking the ball 40 in the open position and which are actuated to release the ball 40 for rotational operating movement thereafter by a predetermined manipulation of the well conduit C. The means L for holding the ball 40 in the open position includes a latch or gripping means G mounted with the housing H and which is movable from a locking position (FIG. 1B) for operably engaging and holding the operator sleeve 30 in the lower position for maintaining the ball 40 open to a released position (FIG. 3A) for enabling operating movement of the operator sleeve 30 to rotate the ball 40 open and closed. The latch means G includes a plurality of locking or latch dogs 50 movably disposed in a corresponding plurality of circumferentially spaced window openings 13c located adjacent the annular shoulder 13b. The latch dogs 50 are movable radially outwardly from an engaged position (FIG. 18) with the operator 30 to a free position (FIGS. 3A & 5) for enabling the operator 30 thereafter to move to and from the upper and lower positions. The downwardly projecting resilient fingers 300 of the operator sleeve 30 are threadedly connected to the sleeve 30 by threaded engagement at 30h for ease of assembly and fabrication, and cooperate with the outer surface 30d of the operator sleeve 30 to form an annular recess 301' having a tapered downwardly facing annular shoulder surface 30j and a plurality of circumferentially spaced upwardly facing tapered annular shoulder surfaces 30k. The recess 301' receives the latch dogs 50 therein to block relative longitudinal movement between the operator sleeve 30 and the latch dogs 50 when the latch dogs are in the locking position. As illustrated in FIGS. 18 and 1C, with the upper tubular section 12 and the lower tubular section 13 in the relative extended position the operator sleeve 30 is held in the lower position relative to pivot pins 31 by the latch dogs 50 for holding the ball 40 in the open position.

The latch means G further includes a retainer sleeve 51 concentrically mounted with the upper tubular section 12, a movable locking or latch member 52 for engaging and maintaining the latch dogs 50 in the locking position and a latch or lock member keeper 53 carried by the lock member 52. The retainer sleeve 51 includes an inner surface 51a shaped or formed with alternating tapered downwardly facing and flat upwardly facing annular shoulders 51b and 510, respectively, to enable upward movement of the latch member 52 towards the fixed sleeve 14 securing the sleeve 51 from upward movement in the bore 0, and which thereafter blocks downward movement of the lock member 52 by engaging the outwardly biased gapped keeper ring 53 mounted in an annular recess 52a of the latch member 52 with the shoulder 51c. As illustrated in FIG. 18, an inner surface 52b of the latch ring 52 engages the plurality of latch dogs 50 to maintain the latch dogs 50 in the engaged position when the ring 52 is adjacent the windows 13c. The latch ring 52 includes a downwardly facing lower annular shoulder 520 which engages both an upwardly facing annular shoulder formed by the window opening 13e of the lower tubular member 13 and an upwardly facing annular shoulder 12r formed by the sleeve 12d adjacent the threads 12g. With this arrangement, relative contracting telescopic movement of the lower tubular section 13 into the upper tubular section 12 will move the latch member 52 upwardly along the retaining sleeve 51 to the position illustrated in FIG. 2A. Thereafter, when the tubular section 12 and 13 move to the relative extended telescopic posi tions (FIG. 3A), the lock member 52 is retained by the shoulder 51c of the sleeve 51 engaging the keeper 53 in the upper position, while the latch dogs 50 along with the lower tubular section 13 move downwardly, for spacing the latch member 52 from the windows He and enabling the latch dogs 30 to move outwardly in response to the camming or wedging action of the lower tapered shoulder surface 30k of the recess 301' to release the operator sleeve 30 and rotate the ball 40 closed. In other words, by sequentially applying the weight of the well conduit C above the housing H to telescopically move the tubular sections 12 and 13 to the contracted position and thereafter enabling the sections 12 and 13 to return to the extended position by lifting the conduit to remove the weight of the upper well conduit C from the housing H, the tool T is actuated to release the ball 40 from the open position for normal operations. Normally, to effect movement of the tubular sections 12 and 13 to the contracted position, it is necessary to lower the drilling string C until the drill bit engages the bottom of the well hole and then continue to lower the well conduit with the rotary drilling equipment (not illustrated) to apply the weight of the drilling string C to the tool to shear the shear pin 16 and actuate the release. Thereafter, by lifting with the rotary drilling equipment the tubular sections 12 and 13 are moved to the extended positions and the ball 40 is released for operation. After release, the sleeve 51 serves to maintain the lock member 52 spaced from the latch dogs 50 to prevent inadvertent locking of the ball 40 in the open position.

In the use and operation of the present invention, the well tool T is assembled in the condition illustrated in FIGS. 1A, 1B and 1C. Reference is again made to my co-pending application Ser. No. 256,194 entitled Pressure Operated Safety Valve With Lock Means, for a more detailed description of the method of assembling the tool T.

The well tool T is connected in the drill string C using the thread connections 10 and 11 as is well known in the art and lowered into the well bore hole until the drill bit engages the bottom thereof. By continuing to lower the drill string C the pin 16 will be sheared and the upper and lower tubular sections, 12 and 13, respectively, will move to the contracted position (FIG. 2A and 2B) for moving the latch dogs 50 and the lock member 52 upwardly along the retainer sleeve 51, until the ball 40 is rotated closed. Thereafter by lifting the drilling string above the tool T the upper and lower tubular sections 12 and 13 will be moved back to the extended position (FIGS. 3A and 3B) which moves or spaces the latch member 52 from the latch dogs 50 as the latch member 52 is retained in the upper position by the keeper 53 engaging the retaining sleeve 51 and the latch dog 50 moves radially outwardly by the camming action of the shoulder 30k to enable the operator 30 to thereafter move upwardly in response to the urging of the spring 35. Leaf springs 50a (FIG. hold the latch dogs 50 in the released position. It will be immediately appreciated that the release means of the present invention in-not requiring rotation of the drill string to actuate is more desirable than that of the prior art as it eliminates the risk of inadvertent and undesired downhole separation of the drilling string C.

When it is desirable to commence drilling operations and circulate drilling fluid down the bore of the drill string and out through the drill bit, the pressure in the bore 0 of the housing H above the ball 40 is increased by the mud pumps at the surface (not illustrated) and the increased pressure is communicated to the upwardly facing annular shoulder a of the operator 30 for urging the operator 30 to move downwardly and rotate the ball 40 to the open position. While this is occurring, the well pressure in the well chamber adjacent the exterior surface 12p of the tool T is communicated into the expansible chamber 34 through the port 12q to provide an offsetting upwardly urging on the shoulder 30e of the operator 30. When the pressure in the bore 0 exceeds the combined upwardly urging of the spring 35 and the well pressure in the chamber 34, the operator 30 will move downwardly to the position illustrated in FIGS. 4A and 4B for enabling flow of fluid down the bore of the drill string and outwardly into the well through the nozzles of the drill bit as is well known in the art.

To insure that the ball will be rotated positively between the open and closed position and will not partially open or flutter between the open and closed position which would regulate the flow and may possibly damage the ball 40 or seat ring 41, the annular shoulder surface 30a is provided with an O-ring 36 for effecting an annular fluid tight seal with the annular shoulder l2n of the sleeve 12 to block communication over the entire annular surface 30a when the operator 30 is in the upper position and the ball is rotated closed. As the operator 30 commences to move to the lower position the annular seal effected by the O-ring 36 is broken enabling the increased pressure in the bore 0 above the ball 40 to be communicated across the entire annular surface 30a and the exposure of the additional surface area of the shoulder surface 30a insures that the operator 30 will move to the lower position and will not stop or equalize in an intermediate position with the ball 40 partially open.

When the combined urging of the pressure communicated into the chamber 34 and the spring 35 exceed the downwardly urging on the operator 30 effected by the pressure in the bore 0 of the housing H, the operator 30 will be moved back to the upper position (FIGS. 3A and 3B) to rotate the ball 40 closed. Such closing may result from increased well pressure in the chamber 34, such as would be present during blowout conditions, or the supply of drilling fluid to the flow passage F of the drill string C may be interrupted for any reason. In other words, the ball 40 is rotated closed in normal operation when incipient pressure conditions indicate that the flow through the bore 0 could reverse to undesirable upwardly flow.

As illustrated in FIG. 4B, the resilient unit 22 is deformed to dampen transmission of longitudinal or vertical vibrations and shock from the lower tubular section 13 to the upper tubular section 12 while the spline connection effected by the ears 13c and l2j transmit the rotary drilling motion through the tool T to the drill bit for enabling drilling operations.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

What is claimed is:

l. A well tool adapted for mounting with a well conduit to control flow of fluid through the well conduit, including:

a housing adapted for connection in a well conduit and having a bore extending therethrough for communicating the flow passage of the well conduit above and below said housing;

bore closure means disposed in said bore for movement to and from an opened position enabling flow of fluid through said bore and a closed position for substantially blocking flow of fluid through said bore;

operator means mounted with said housing for moving said bore closure means to and from the open and closed position in response to the urging of fluid pressure for effecting desired flow through the well conduit; and

means mounted with said housing for releasably holding said bore closure means initially in the open position and actuated to release said bore closure means for fluid pressure operation by said operator means by a predetermined manipulation of said housing wherein bore closure means movement to control the flow is enabled.

2. The structure as set forth in claim 1, wherein:

the housing is manipulated to release said bore closure means for movement in response to sequentially applying and then removing the weight of the well conduit above said housing to said housing.

3. The structure as set forth in claim 1, wherein:

the housing is manipulated to release said bore closure means for movement in response to sequentially lowering and then lifting the well conduit in the well.

4. The structure as set forth in claim 1, wherein:

said means for holding said bore closure means in the open position includes latch means operably connected with said bore closure means and movably mounted with said housing between a locking position for holding said bore closure means in the open position and release position for enabling movement of said bore closure means to the closed position.

5. The structure as set forth in claim 1, including:

an operator member mounted with said housing and movable to and from a first position for effecting movement of said bore closure means to the open position and to and from a second position for effecting movement of said bore closure means to the closed position wherein movement of said operator member controls flow of fluid through the well tool.

6. The structure as set forth in claim 5, wherein:

said means for holding said bore closure means in the open position includes a latch means mounted with said housing and movable from a locking position operably engaging said operator to hold said operator in the first position to a released position for enabling operating movement of said operator member wherein said bore closure means is released for movement.

7. A well tool, including:

a housing adapted for connection in a well conduit having a bore extending therethrough for communicating the flow passages of the well conduit above and below said housing;

bore closure means disposed in said bore for movement to and from an opened position enabling flow of fluid through said bore and a closed position for substantially blocking flow of fluid through said bore;

means for releasably holding said bore closure means in the open position actuated to release said bore closure means by a predetermined manipulation of the well conduit;

said means for holding said bore closure means in the open position includes a latch means mounted with said housing and movable from a locking position operably engaging said operator to hold said operator in the first position to a released position for enabling operating movement of said operator member;

said housing having a first housing portion; and

said housing having a second housing portion connected with said first housing portion and movable relative thereto to and from an extended position and a contracted position, said second housing por tion mounting said latch means to effect movement of said latch means from the locking position to the released position for enabling movement of said bore closure means when said second housing portion sequentially moves to the contracted position and the extended position wherein said bore closure means is released.

8. The structure as set forth in claim 7, wherein:

said first housing portion connected with said second housing position to enable relative longitudinal movement therebetween while blocking relative circumferential rotational movement therebetween wherein the well too] is operable in a rotary drill string.

9. The structure as set forth in claim 7, including:

means for dampening transmission of vibrations and shocks from said second housing portion to said first housing portion during drilling operations.

10. The structure as set forth in claim 7, wherein said latch means includes:

a. said second housing portion having a window opening formed therein;

b. a latch dog disposed in said opening and movable from an engaged position with said operator for holding said operator in the first position to a free position for enabling said operator to thereafter move to and from the first position and the second positions wherein movement of 'said bore closure means is enabled.

11. The structure as set forth in claim 10, including:

a. a lock member mounted with said housing and movable from a locked position for securing said latch dog in the engaged position to a released position enabling said latch dog to move to the free position wherein said bore closure means is released; and

b. said first housing portion engaging said lock member when said second housing portion is in the contracted position to thereafter move said lock member to the released position when said second housing portion moves to the extended position wherein said latch dog moves to the free position.

12. The structure as set forth in claim 10, wherein:

a. said second housing portion having a plurality of circumferentially spaced window openings formed therein; and

b. a corresponding plurality of latch dogs disposed in each of said openings and movable from the engaged position to the free position.

13. The structure as set forth in claim 5, wherein:

said bore closure means includes a ball member having a flow port formed therethrough for rotating to and from the open position to align said flow port with said bore for enabling the flow of fluid there through and the closed position for blocking the flow of fluid with said ball member.

14. The structure as set forth in claim 13, including:

pivot means engaging said ball member and co-acting with said operator member for rotating said ball member to and from the open and closed position.

15. The structure as set forth in claim 13, wherein:

said ball member moves longitudinally in rotating to and from the open and closed positions.

16. A well tool, including:

a housing adapted for connection in a well conduit having a bore extending therethrough for communicating the flow passages of the well conduit above and below said housing;

bore closure means disposed in said bore for movement to and from an opened position enabling flow of fluid through said bore and a closed position for substantially blocking flow of fluid through said bore; and

means for releasably holding said bore closure means in the open position actuated to release said bore closure means by a predetermined manipulation of the well conduit;

an operator member mounted with said housing and movable to and from a first position for effecting movement of said bore closure means to the open position and to and from a second position for effecting movement of said bore closure means to the closed position.

said operator member having a first pressure responsive surface communicating with said bore of said housing above said bore closure means to move said operator to the first position in response to the fluid pressure urging thereon; and

said operator member having a second pressure responsive surface communicating with an area adjacent an exterior surface of said housing to move said operator to the second position in response to the fluid pressure urging thereon wherein the well tool operates in response to well pressures to control the flow. 17. The structure as set forth in claim 16, including:

spring means mounted with said housing for urging movement of said operator member to the second position for maintaining the bore closure means in the closed position when the urging of the fluid pressure on said first pressure responsive surface is less than the combined urging of the spring means and the fluid pressure of said second pressure responsive surface.

18. The structure as set forth in claim 16, including:

averts partial opening of said bore closure means. 

1. A well tool adapted for mounting with a well conduit to control flow of fluid through the well conduit, including: a housing adapted for connection in a well conduit and having a bore extending therethrough for communicating the flow passage of the well conduit above and below said housing; bore closure means disposed in said bore for movement to and from an opened position enabling flow of fluid through said bore and a closed position for substantially blocking flow of fluid through said bore; operator means mounted with said housing for moving said bore closure means to and from the open and closed position in response to the urging of fluid pressure for effecting desired flow through the well conduit; and means mounted with said housing for releasably holding said bore closure means initially in the open position and actuated to release said bore closure means for fluid pressure operation by said operator means by a predetermined manipulation of said housing wherein bore closure means movement to control the flow is enabled.
 2. The structure as set forth in claim 1, wherein: the housing is manipulated to release said bore closure means for movement in response to sequentially applying and then removing the weight of tHe well conduit above said housing to said housing.
 3. The structure as set forth in claim 1, wherein: the housing is manipulated to release said bore closure means for movement in response to sequentially lowering and then lifting the well conduit in the well.
 4. The structure as set forth in claim 1, wherein: said means for holding said bore closure means in the open position includes latch means operably connected with said bore closure means and movably mounted with said housing between a locking position for holding said bore closure means in the open position and release position for enabling movement of said bore closure means to the closed position.
 5. The structure as set forth in claim 1, including: an operator member mounted with said housing and movable to and from a first position for effecting movement of said bore closure means to the open position and to and from a second position for effecting movement of said bore closure means to the closed position wherein movement of said operator member controls flow of fluid through the well tool.
 6. The structure as set forth in claim 5, wherein: said means for holding said bore closure means in the open position includes a latch means mounted with said housing and movable from a locking position operably engaging said operator to hold said operator in the first position to a released position for enabling operating movement of said operator member wherein said bore closure means is released for movement.
 7. A well tool, including: a housing adapted for connection in a well conduit having a bore extending therethrough for communicating the flow passages of the well conduit above and below said housing; bore closure means disposed in said bore for movement to and from an opened position enabling flow of fluid through said bore and a closed position for substantially blocking flow of fluid through said bore; means for releasably holding said bore closure means in the open position actuated to release said bore closure means by a predetermined manipulation of the well conduit; said means for holding said bore closure means in the open position includes a latch means mounted with said housing and movable from a locking position operably engaging said operator to hold said operator in the first position to a released position for enabling operating movement of said operator member; said housing having a first housing portion; and said housing having a second housing portion connected with said first housing portion and movable relative thereto to and from an extended position and a contracted position, said second housing portion mounting said latch means to effect movement of said latch means from the locking position to the released position for enabling movement of said bore closure means when said second housing portion sequentially moves to the contracted position and the extended position wherein said bore closure means is released.
 8. The structure as set forth in claim 7, wherein: said first housing portion connected with said second housing position to enable relative longitudinal movement therebetween while blocking relative circumferential rotational movement therebetween wherein the well tool is operable in a rotary drill string.
 9. The structure as set forth in claim 7, including: means for dampening transmission of vibrations and shocks from said second housing portion to said first housing portion during drilling operations.
 10. The structure as set forth in claim 7, wherein said latch means includes: a. said second housing portion having a window opening formed therein; b. a latch dog disposed in said opening and movable from an engaged position with said operator for holding said operator in the first position to a free position for enabling said operator to thereafter move to and from the first position and the second positions wherein movement of said bore closure means is enabled.
 11. The structure as set forth in claim 10, including: a. a lock member mounted with said housing and movable from a locked position for securing said latch dog in the engaged position to a released position enabling said latch dog to move to the free position wherein said bore closure means is released; and b. said first housing portion engaging said lock member when said second housing portion is in the contracted position to thereafter move said lock member to the released position when said second housing portion moves to the extended position wherein said latch dog moves to the free position.
 12. The structure as set forth in claim 10, wherein: a. said second housing portion having a plurality of circumferentially spaced window openings formed therein; and b. a corresponding plurality of latch dogs disposed in each of said openings and movable from the engaged position to the free position.
 13. The structure as set forth in claim 5, wherein: said bore closure means includes a ball member having a flow port formed therethrough for rotating to and from the open position to align said flow port with said bore for enabling the flow of fluid therethrough and the closed position for blocking the flow of fluid with said ball member.
 14. The structure as set forth in claim 13, including: pivot means engaging said ball member and co-acting with said operator member for rotating said ball member to and from the open and closed position.
 15. The structure as set forth in claim 13, wherein: said ball member moves longitudinally in rotating to and from the open and closed positions.
 16. A well tool, including: a housing adapted for connection in a well conduit having a bore extending therethrough for communicating the flow passages of the well conduit above and below said housing; bore closure means disposed in said bore for movement to and from an opened position enabling flow of fluid through said bore and a closed position for substantially blocking flow of fluid through said bore; and means for releasably holding said bore closure means in the open position actuated to release said bore closure means by a predetermined manipulation of the well conduit; an operator member mounted with said housing and movable to and from a first position for effecting movement of said bore closure means to the open position and to and from a second position for effecting movement of said bore closure means to the closed position. said operator member having a first pressure responsive surface communicating with said bore of said housing above said bore closure means to move said operator to the first position in response to the fluid pressure urging thereon; and said operator member having a second pressure responsive surface communicating with an area adjacent an exterior surface of said housing to move said operator to the second position in response to the fluid pressure urging thereon wherein the well tool operates in response to well pressures to control the flow.
 17. The structure as set forth in claim 16, including: spring means mounted with said housing for urging movement of said operator member to the second position for maintaining the bore closure means in the closed position when the urging of the fluid pressure on said first pressure responsive surface is less than the combined urging of the spring means and the fluid pressure of said second pressure responsive surface.
 18. The structure as set forth in claim 16, including: a fluid seal positioned on said first pressure responsive surface to block communication of the fluid pressure in said bore of said housing above said bore closure means to a portion of said first pressure responsive surface when said operator member is in the second position and which enables communication of the fluid pressure in said bore of said housing above said bore closure means with said portion of said first pressure responsive surface when said operator commences to move to the first position wherein said operator movement averts partial opening of said bore closure means. 